4.1 Possible anomaly of the forearms and lower limbs
Both the proximal and the distal epiphyses of the right humerus and the preserved distal epiphysis of the left humerus are normal in shape and structure. The right and left forearms show partially deformed and underdeveloped epiphyses. The left and right radii are shorter than normal and moderately bowed.
The left femur is fractured and a small radiopaque body (1.5-2 cm, HF density between 1.000 and 2.000) is observable at the fracture edge of its distal epiphysis. This structure seems to be an intrusive stone (fig. 12).
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Figure 12 Results of a CT scan performed on Zweeloo Woman’s skeletal remains. The viscera were positioned between the lower limbs. |
Both the right femur and the right fibula show marked bowing. There are signs of coxa valga. The left leg appears to be shorter than its counterpart.
Both lower legs appear to be underdeveloped in comparison with the femora. This difference is however less evident than that observed in the forearms.
Proximal portions of the limbs, hands and feet show no abnormality of size, though there is possible evidence of reactive change in the bones of the feet caused by some degree of abnormal gait. There is no evidence of nutritional deficiency or infectious illness, and no other part of the skeleton appears to be affected.
The X-ray features of dyschondrosteosis in living patients and in dry bones are based on a spectrum of manifestations. The features typical of DCS patients that are observable in Zweeloo Woman include: 1) shortening of the radius extremity with hypodevelopment of both proximal and distal epyphises as compared with the normal standard for age and in relation to the size of the other bones; 2) double (lateral and dorsal) bowing of the radius which involves the entire diaphysis but is more marked at the distal end (Madelung’s deformity; Langer 1965); 3) shortening of the tibia in relation to the femur, which results in mild dwarfism. This pattern of shortening in the middle segment of extremities is referred to as mesomelia (Langer 1965).
The skull, the spine and the pelvis are radiologically normal in all cases described in the literature in which these bones have been studied, those of Zweeloo Woman included.
Surprisingly few bog bodies have been reported as showing anomalies and, where observed, the disease is mostly associated with adult individuals (Brothwell & Gill-Robinson, 2002, 120).
Following Lynnerup (2010, 444) “acid bog diagenetics mean that bone will be demineralised, become pliable and, upon subsequent excavation and drying out, also shrink and warp. This means that under these conditions, etiological attribution of pathology and trauma lack certainty”.
The greatest uncertainty in the case of Zweeloo Woman is essentially her ‘true’ stature. The great discrepancy between the value of 170 cm quoted shortly after her excavation (1952) and the values of 152 and 155 obtained in 1995 and 2009-2011 is clearly an issue.
No written records of the stature measurements carried out at the time of exhumation are available. The only scientific information is that provided by Stoddart, who interpreted the asymmetry identified between one side of the body and its counterpart as due to shrinkage.
The data obtained by means of AFM and histology provide evidence of slight degradation of collagen fibrils and moderate bone demineralisation, implying shrinkage. The possible diagnosis of Léri-Weill dyschondrosteosis should however not be totally rejected.
Since the taphonomic impact of the acidic peat bog environment on human remains is still not well understood (Janaway et al. 2003, 56-59; Gill-Frerking & Healey 2011, 69-74), the possibilities of taphonomy and pseudopathology must always be considered (Gill-Robinson 2003, 46). Similarly, bone abnormalities should not always be assumed to be due to bog taphonomy. The possibility of skeletal disorders pre-existing the taphonomic process should also be considered.
To sum up, the bone morphology and radiological findings indicate a possible case of Léri-Weill dyschondrosteosis.